The present invention relates to electrical components of the type mounted on a circuit board such as, for example, resistors, capacitors, photo detectors and photo emitters such as light emitting diodes (LEDs). These latter devices may be mounted individually or in closely spaced arrangement in an array where relatively high illumination is required in a relatively small area. In such arrays, it has been found difficult to remove the heat at a sufficient rate to prevent the LEDs from overheating and resultant premature failure.
Presently LEDs are limited in further increases in illumination power by the inability to keep the junction temperature within a range that the efficiency and life expectancy of the device is acceptable.
Currently, it has been found desirable to employ LEDs in automotive illumination applications. LEDs are desirable in such applications because of their higher efficiency in terms of light intensity output as a function of the electrical energy input as compared with incandescent bulbs. However, LEDs have the disadvantage that they have a much lower operating temperature limit than incandescent bulbs. In such automotive applications the environment in which the LEDs must operate subjects them to ambient temperatures higher than typically encountered in indoor stationary applications.
In applications where the LEDs are arranged in closely spaced arrays, it has been desired to find a way or means of economically removing the heat from the diode array in order to prevent exceeding the operating temperature of the individual LEDs. This latter problem is particularly troublesome where the LEDs are mounted directly on a circuit board for economies of space and ease of manufacture. This has been desired to find a way or means of providing increased cooling for an array of closely spaced circuit components, particularly LEDs mounted directly on a circuit board.